The affix khaś comes after the verb tud 'to strike' when vidhu 'the moon' or arus 'a wound' is the word in composition with it as object.,
As विधुन्तुदः राहुः 'the Rahu that eclipses the moon; अरुन्तुदः 'corrosive, wounding the vital parts'. For the addition of the augment मुम् after the word अरुस्, see 6.3.67.,